West Nile virus (WNV) has spread rapidly across North America, resulting in human deaths and in the deaths of untold numbers of birds, mammals, and reptiles. The virus has reached Central America and the Caribbean and may spread to Hawaii and South America. Although tens of thousands of birds have died, and studies of some bird species show local declines, few regionwide declines can be attributed to WNV. Predicting future impacts of WNV on wildlife, and pinpointing what drives epidemics, will require substantial additional research into host susceptibility, reservoir competency, and linkages between climate, mosquitoes, and disease. Such work will entail a collaborative effort between scientists in governmental research groups, in surveillance and control programs, and in nongovernmental organizations. West Nile virus was not the first, and it will not be the last, exotic disease to be introduced to the New World. Its spread in North America highlights the need to strengthen animal monitoring programs and to integrate them with research on disease ecology.

The application of technologies from functional genomics to ecological research will add new power to the tools that are currently available for the study of an organism's response to the environment. One particularly important area in which this technology will have a large impact is the study of human and environmental health. In the future, scientists may rely on changes in gene or protein expression in an organism as an early warning of exposure to and effects of different stressors in the environment and as an indicator of the overall health of organisms in the environment.

Hierarchical and branching river networks interact with dynamic watershed disturbances, such as fires, storms, and floods, to impose a spatial and temporal organization on the nonuniform distribution of riverine habitats, with consequences for biological diversity and productivity. Abrupt changes in water and sediment flux occur at channel confluences in river networks and trigger changes in channel and floodplain morphology. This observation, when taken in the context of a river network as a population of channels and their confluences, allows the development of testable predictions about how basin size, basin shape, drainage density, and network geometry interact to regulate the spatial distribution of physical diversity in channel and riparian attributes throughout a river basin. The spatial structure of river networks also regulates how stochastic watershed disturbances influence the morphology and ages of fluvial features found at confluences.

Pearly mussels (Unionacea) are widespread, abundant, and important in freshwater ecosystems around the world. Catastrophic declines in pearly mussel populations in North America and other parts of the world have led to a flurry of research on mussel biology, ecology, and conservation. Recent research on mussel feeding, life history, spatial patterning, and declines has augmented, modified, or overturned long-held ideas about the ecology of these animals. Pearly mussel research has begun to benefit from and contribute to current ideas about suspension feeding, life-history theory, metapopulations, flow refuges, spatial patterning and its effects, and management of endangered species. At the same time, significant gaps in understanding and apparent paradoxes in pearly mussel ecology have been exposed. To conserve remaining mussel populations, scientists and managers must simultaneously and aggressively pursue both rigorous research and conservation actions.

Mathematical models have a long history of use for understanding ecological systems. In a recent book, A New Kind of Science, Steve Wolfram calls into question traditional modeling approaches and calls for the increased application of cellular automata (CA) models in all areas of scientific inquiry. With reference to Wolfram's book, we review the past uses of CA models in ecology and discuss the relative utility of using traditional models versus CA models to understand ecological communities.

Since their first use in the mid-1980s, passive integrated transponder devices (PIT tags) have allowed innovative investigations into numerous biological traits of animals. The tiny, coded markers injected into individual animals allow assessment of growth rates, movement patterns, and survivorship for many species in a manner more reliable than traditional approaches of externally marking animals for identification. PIT tags have also been used to confirm the identity of zoo animals, pets, and protected species that have been illegally removed from the wild. New approaches with PIT tags herald advances in physiology and conservation biology, as well as greater understanding of social interactions among individuals in a population. Despite their current limitations, including high purchase cost, low detection distance, and potential tag loss in some circumstances, PIT tags offer many opportunities to unravel animal mysteries that heretofore could not be addressed effectively.

Biodiversity research has been the mainstay of natural history museums, but the traditional uses of biological collections in taxonomy, systematics, and evolutionary biology account for only part of these collections' value. Biological collections today are meeting diverse needs. New uses for specimens—as “biological filter paper,” for example—have little relationship to the taxon-oriented research on which collections are based, yet they often have tremendous import for helping us understand changes in populations, species, and the environment. As the major issues in exploration and systematics are resolved and society's interest in biodiversity wavers, museums need to embrace important new uses for natural history collections and, with new partners, begin laying new foundations for a postbiodiversity future. Proactively opening a domain focused on exploration and basic biodiversity to an increase in applied research can enable museums to grow to meet present and future challenges and to bring their true strengths, their collections, to bear on broader issues for both science and society.